This is an unmarked dark blue cotton denim workwear apron. I don’t think it’s very old because the upper edge is finished with a white synthetic fabric strap. 80s? 90s?  
 
The apron is made in 3 pieces with the center piece gently flared from hip to hem. The two front seams are topstitched on front and chainstitch on the backside. White twill tape straps are sewn on at the bib, then crisscross in back and feed thru a large grommet at both sides. The wearer can tie the straps in back or the front, depending on your own size. 
 
Pre-owned, no real sign of use but the denim isn’t super stiff.
 
Measurements are—
Center front length- 36”
Waist 25” across between the grommet edges
Hem- 36.5 
Tie ends- adjustable